IPN 2022 May

Page 24

How Common is Shingles? pain, and cerebrovascular events. Postherpetic neuralgia is the most common complication, occurring in about one in five patients.


Interview with Theresa Lowry Lehnen (GPN, RNP, PhD) Clinical Nurse Specialist and Associate Lecturer South East Technological University (SETU) Shingles is an infection of a nerve and the area of skin around it. It is caused by the herpes varicella-zoster virus, which also causes chickenpox. Most people have chickenpox in childhood, but after the illness has gone, the virus remains dormant in the nervous system. The immune system keeps the virus under control, but later in life it can be reactivated and cause shingles. It is uncertain exactly why the shingles virus is reactivated at a later stage in life like this. It may be due to having lowered immunity as a result of aging, stress or of an immunocompromising condition. It is estimated that about 3 people in every 1,000 have shingles in the UK every year. The figure for Ireland is likely to be similar. Shingles can occur at any age, but is most common in people who are over 50 years of age.Among people who are over 80 years of age, about 11 people in every 1,000 have shingles each year.

VZV is a double stranded DNA human neurotrophic alphaherpes virus. Theresa adds, “Any person who contracted varicella infection (chicken pox) through natural infection by the varicella zoster virus (VZV) or the varicella vaccine can develop herpes zoster. Once the VZV primary infection resolves, it forms a lifelong latency within the cranial or dorsal root ganglia. Herpes zoster infection occurs after reactivation of the latent VZV. The cause of reactivation of VZV is not fully understood, but risk factors include advancing age, stress and immunocompromised status from conditions such as HIV-1 infection, lymphoma, leukaemia, bone marrow transplant, solid organ transplant, and immunosuppressive medications. Other risk factors include Caucasian race, female sex, physical trauma, diabetes mellitus, a prior history and family history of HZ.” During latent varicella, specific varicella zoster memory T cells are produced, suppressing the virus in the sensory root ganglia cells. Over time, the memory T-cell immunity begins to weaken and decline. This decline below the “zoster threshold” leads to reactivation of the virus and development of the herpes zoster infection. Reactivation occurs when VZV is able to overpower immune controls and spreads through the affected ganglions and nerves to reach the skin and manifest as HZ.

Risk factors The immune system becomes less effective with age and ageing increases the risk of a person developing herpes zoster. She adds, “Depression increases the risk of developing HZ because it affects the immune system. Statins are known to affect the immune system and increases the risk of HZ by 13%. In people with diabetes; the rate of herpes zoster is higher among statins users. People who have taken statins in the past have a higher risk of developing HZ than those who have not.”

It is much less common in children. We recently spoke to Theresa Lowry Lehnen, Clinical Nurse Specialist and Associate Lecturer South East Technological University to find out more about this condition, and what community pharmacies need to be aware of in helping to manage and treat this population. “When the immune system is compromised the virus can re-activate. When reactivated, the virus travels along the affected sensory nerve to reach the corresponding dermatome in the skin where a vesicular rash develops,” Theresa explains. “Prior to the rash appearance, the frequent prodromal itching or pain can lead to erroneous and delayed diagnosis. The vesicles pustulate and then scab, usually within 2–4 weeks, but residual scarring is common.” Once the virus activates, it can lead to a painful, blistery rash and the pain can last for months to years. Worryingly, she adds that more than 10% of patients who develop shingles will experience a complication, including blindness, neuropathic


Diseases such as human immunodeficiency disease (HIV), and lymphoma and medications such as steroids depress the immune system and increase the risk of HZ and other infections.

Symptoms, Presentation and Diagnosis Early symptoms of herpes zoster including headache, fever and malaise are nonspecific, and may result in an incorrect diagnosis. These symptoms are commonly followed by sensations of burning pain, itching, hyperesthesia, or paraesthesia. Pain can be mild to severe in the affected dermatome with sensations such as stinging, tingling, aching, numbing or throbbing interspersed with quick stabs of agonizing pain. “After one to two days, but sometimes as long as three weeks, the initial phase is followed by the appearance of the characteristic skin rash. The pain and rash most commonly occur on the torso but can appear on the face, eyes, or other parts of the body,” Theresa explains. “A dermatome is an area of skin that is mainly supplied by a single spinal nerve. Usually limited to one (sometimes two) dermatome, a maculopapular rash occurs in a stripe or beltlike pattern on one side of the body and does not cross the midline. Later the rash becomes vesicular, forming small blisters filled with a serous exudate, as the fever and general malaise continue. The painful vesicles eventually become cloudy or darkened as they fill with blood and crust over within seven to ten days. Usually the crusts fall off and the skin heals, but sometimes, after severe blistering, scarring and discoloration remain. Less commonly, the rash can affect three or more dermatomes (disseminated zoster). “A prodrome of tingling of the forehead may occur. In addition to the painful forehead rash, signs and symptoms may include severe ocular pain; marked eyelid oedema; conjunctival, episcleral, and circumcorneal conjunctival hyperaemia; corneal oedema; and photophobia. Zoster of the trigeminal nerve should be considered in a patient with a prior history of